ActiveReports gives you complete control to bind reports to any type of data source, including arrays, through its programmable object model. You can create a report without setting the report's data source and load the data from your data source into the report's controls at run time. The Fields property allows data binding between the controls and the run-time fields. It also allows the control's DataField property to be set to any of the run-time defined names. The DataInitialize and FetchData events are used to define the run-time fields and feed the data values of these fields so they can be used with unbound controls.

This walkthrough illustrates the fundamentals of using the DataInitialize and FetchData events to set up an unbound report.

This walkthrough is split into the following activities:

• Adding an ActiveReport to a Visual Studio project
• Adding code to connect the report to a data source
• Adding code to disconnect the data source
• Adding controls to contain the data
• Using the DataInitialize event to add fields to the report's fields collection
• Using the FetchData event to populate the report fields
• Viewing the report 

To complete the walkthrough, you must have access to the NorthWind database (NWind.mdb).

When you have completed this walkthrough, you will have a report that looks similar to the following.

Adding an ActiveReport to a Visual Studio project

To add an ActiveReport to your project

1. Open a new project in Visual Studio.
2. Click on Project > Add New Item.
3. Select ActiveReports file and rename the file rptUnbound.
4. Click Open.

Adding code to connect the report to a data source

To write the code in Visual Basic

• Right-click in any section of the design window of rptUnbound, and select View Code to display the code view for the report. At the top left of the code view for rptUnbound, click the drop-down arrow and select (rptUnbound Events). At the top right of the code window, click the drop-down arrow and select ReportStart. This creates an event-handling method for rptUnbound's ReportStart event. Add code to the handler to:
• Set the data source connection string
• Set the data source SQL query
• Open the connection to create the DataReader

To write the code in C#

• Click in the gray area below rptUnbound to select the report. Click on the events icon in the Properties window to display available events for the report. Double-click ReportStart. This creates an event-handling method for rptUnbound's ReportStart event. Add code to the handler to:
  • Set the data source connection string
  • Set the data source SQL query
  • Open the connection to create the DataReader

  The following example shows what the code for the method looks like.

  ' Visual Basic
  Dim m_cnnString As String
  Dim sqlString As String
  Dim m_reader As OleDb.OleDbDataReader
  Dim m_cnn As OleDb.OleDbConnection
  Private Sub rptUnbound_ReportStart(ByVal sender As Object, ByVal e As System.EventArgs) _
  	Handles Me.ReportStart
          m_cnnString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Program Files\ _
  		Data Dynamics\ActiveReports for .NET 2.0\Data\NWIND.MDB;Persist _
  		Security Info=False"
          sqlString = "SELECT * FROM categories INNER JOIN products ON _
  		categories.categoryid = products.categoryid ORDER BY _
  		products.categoryid, products.productid"
          m_cnn = New OleDb.OleDbConnection(m_cnnString)
          Dim m_Cmd As New OleDb.OleDbCommand(sqlString, m_cnn)
          If m_cnn.State = ConnectionState.Closed Then
              m_cnn.Open()
           End If
          m_reader = m_Cmd.ExecuteReader()
  End Sub

  //C#
  private OleDb.OleDbConnection m_cnn;
  private OleDb.OleDbDataReader  m_reader;
  private void rptUnbound_ReportStart(object sender, System.EventArgs eArgs)
  {
  
  	string m_cnnString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Program 
  		Files\Data Dynamics\ActiveReports for .NET 2.0\Data\NWIND.MDB;Persist 
  		Security Info=False";
  	string sqlString = "SELECT * FROM categories INNER JOIN products ON 
  		categories.categoryid = products.categoryid ORDER BY products.categoryid,
  		products.productid";
  	m_cnn = new OleDbConnection(m_cnnString);
  	OleDbCommand m_Cmd = new OleDbCommand(sqlString,m_cnn);
  	if(m_cnn.State == ConnectionState.Closed)
  	{
  		m_cnn.Open();
  	}
  	m_reader = m_Cmd.ExecuteReader();
  }

Adding code to disconnect the data source

To write the code in Visual Basic

• Right-click in any section of the design window of rptUnbound, and select View Code to display the code view for the report. At the top left of the code view for rptUnbound, click the drop-down arrow and select (rptUnbound Events). At the top right of the code window, click the drop-down arrow and select ReportEnd. This creates an event-handling method for rptUnbound's ReportEnd event. Add code to the handler to close the database Connection and DataReader objects. 

To write the code in C#

• Click in the gray area below rptUnbound to select the report. Click the events icon in the Properties window to display available events for the report. Double-click ReportEnd. This creates an event-handling method for rptUnbound's ReportEnd event. Add code to the handler to close the database Connection and DataReader objects. 

  The following example shows what the code for the method looks like.

  ' Visual Basic
    Private Sub rptUnbound_ReportEnd(ByVal sender As Object, ByVal e As System _
    	.EventArgs) Handles Me.ReportEnd
          m_cnn.Close()
          m_reader.Close()
      End Sub

  //C#
  private void rptUnbound_ReportEnd(object sender, System.EventArgs e)
  {
  	m_cnn.Close();
  	m_reader.Close();
  
  }

Adding controls to the report to contain data

To add controls to the report

• Add the following controls to the Detail section of rptUnbound:

  Control	DataField	Name	Text/Caption	Location
  TextBox	ProductName	txtProductName	Product Name	0, 0.4
  TextBox	UnitsInStock	txtUnitsInStock	Units in Stock	4.75, 0.4
  Label	(Empty string)	lblProductName	Product Name	0, 0
  TextBox	Description	txtDescription	Description	1.8, 0.7
  Label	(Empty string)	lblCategoryDescription	Category Description	0, 0.7
  Label	(Empty string)	lblUnitsInStock	Units in Stock	4.75, 0
  Label	(Empty string)	lblCategoryName	Category Name	3.2, 0
  TextBox	CategoryName	txtCategoryName	Category Name	3.2, 0.4
  Line	(Empty string)	Line1	(Empty string)	X1 = 0 Y1 = 1 X2 = 6.5 Y2 = 1

Using the DataInitialize event to add fields

To write the code in Visual Basic

• Right-click in any section of the design window of rptUnbound, and click on View Code to display the code view for the report. At the top left of the code view for rptUnbound, click the drop-down arrow and select (rptUnbound Events). At the top right of the code window, click the drop-down arrow and select DataInitialize. This creates an event-handling method for rptUnbound's DataInitialize event. Add code to the handler to add fields to the report's Fields collection.

To write the code in C#

• Click in the gray area below rptUnbound to select the report. Click on the events icon in the Properties window to display available events for the report. Double-click DataInitialize. This creates an event-handling method for rptUnbound's DataInitialize event. Add code to the handler to add fields to the report's Fields collection.

  The following example shows what the code for the method looks like.

  ' Visual Basic
  Private Sub rptUnbound_DataInitialize(ByVal sender As Object, ByVal e As _
  	System.EventArgs) Handles Me.DataInitialize
          Fields.Add("CategoryName")
          Fields.Add("ProductName")
          Fields.Add("UnitsInStock")
          Fields.Add("Description")
  End Sub

  //C#
  private void rptUnbound_DataInitialize(object sender, System.EventArgs eArgs)
  {
  	Fields.Add("CategoryName");
  	Fields.Add("ProductName");
  	Fields.Add("UnitsInStock");	
  	Fields.Add("Description");
  }

Using the FetchData event to populate the report fields

To write the code in Visual Basic

• Right-click in any section of the design window of rptUnbound, and click on View Code to display the code view for the report. At the top left of the code view for rptUnbound, click the drop-down arrow and select (Base Class Events). At the top right of the code window, click the drop-down arrow and select FetchData. This creates an event-handling method for rptUnbound's FetchData event. Add code to the handler to:
  • Retrieve information to populate the report fields

To write the code in C#

• Click in the gray area below rptUnbound to select the report. Click on the events icon in the Properties window to display available events for the report. Double-click FetchData. This creates an event-handling method for rptUnbound's FetchData event. Add code to the handler to:
  • Retrieve information to populate the report fields

  The following example shows what the code for the method looks like.

  ' Visual Basic
    Private Sub rptUnbound_FetchData(ByVal sender As Object, ByVal eArgs As DataDynamics._
    	ActiveReports.ActiveReport.FetchEventArgs) Handles MyBase.FetchData
          Try
              m_reader.Read()
              Me.Fields("CategoryName").Value = m_reader("CategoryName")
              Me.Fields("ProductName").Value = m_reader("ProductName")
              Me.Fields("UnitsInStock").Value = m_reader("UnitsInStock")
              Me.Fields("Description").Value = m_reader("Description")
          	   eArgs.EOF = False
          Catch ex As Exception
              eArgs.EOF = True
          End Try
      End Sub

  //C#
  private void rptUnbound_FetchData(object sender, DataDynamics.ActiveReports.ActiveReport.
  	FetchEventArgs eArgs)
  {
  	try
  	{
  		m_reader.Read();
  		Fields["CategoryName"].Value = m_reader["CategoryName"].ToString();
  		Fields["ProductName"].Value = m_reader["ProductName"].ToString();
  		Fields["UnitsInStock"].Value = m_reader["UnitsInStock"].ToString();
  		Fields["Description"].Value = m_reader["Description"].ToString();
  		eArgs.EOF = false;
  	}
  	catch
  	{
  		eArgs.EOF = true;
  	}
  }

Note: The DataInitialize and FetchData events are the only events in which the Fields collection should ever be referenced.

Viewing the report

To view the report

1. Add the ActiveReports viewer control to a Windows Form.
2. Add the code needed to set the viewer document equal to the report document. See Using the ActiveReports WinForm Viewer for help.

Samples | Walkthroughs

 

 

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